Electromagnetic relays



s. F. SMITH ELECTROMAGNETIC RELAYS Sept. 3, 1963 Filed Sept. 29, 1960 I @5, 2 INVENIDR YDNEY Elmer: uru BY mm ml 37 MN United rates Patent The present invention relates to electromagnetic relays and particularly though not exclusively to multiple relay 7 assemblies.

According to the invention an electromagnetic relay comprises an E-shaped electromagnet having energising windings on its middle limb and on one outer limb, and a flat armature carried by one or more moving contact springs of a contact springset of the relay and rockably engaging the other outer limb of the electromagnet to form an extension thereof, said armature being arranged to cooperate with a pole piece which bridges the limbs having energising windings thereon and extends towards the armature.

To provide a multiple relay assembly a plurality of relays according to the invention can have the yoke portions of their E-shaped electromagnets (that is the portion from which said limbs extend) fastened to or integrally constituted by a common magnetic member. A common non-magnetic member can then be provided to clamp the pole pieces of the several relays to the limbs which they bridge and common insulating members utilized to support the fixed and moving contact springs of the several spring sets.

In order that the invention may be more clearly understood reference will now be made to the accompanying drawings in which:

FIG.v 1 shows .a side elevation of a single relay embodying the invention, and

FIG. 2 shows a perspective view of two relays embodying the invention arranged to form a multiple relay assembly.

Referring in the first instance to FIG. 1 a fiat yoke 1 of magnetic material is provided with three upstanding limbs 2, 3 and 4 arranged substantially parallel to each other to form an E-shaped construction. The middle limb 3 and one outer limb Z are each provided with an energising winding 6, formed for example, by an insulated conductor wound on a bobbin 7 moulded from synthetic resin and arranged to be a sliding fit over a limb Z or 3. The free end of the other limb 4 is bent outwardly substantially normal to the remainder of the limb 4, and its extremity is formed into a knife edge 8. A flat pole piece 9 of magnetic material is arranged to bridge the free ends of the limbs 2. and 3, and is clamped in this position by a non-magnetic bar 10 of L-shaped cross-section which is fastened to the limb 2 by means of a screw ll. Movement of the bobbins 7 on the limbs 2 and 3 is prevented by a strip 12 of deformable material, such as for example rubber, which is trapped between the upper ends of the bobbins 7 and the lower face of the pole piece 9. A contact spring set 13, comprising a number of fixed contact springs 14- secured by a moulded strip 15 of insulating material intermediate their ends and a like number of co-operating moving contact springs 16 secured by a similar moulded strip 1'7, is fastened to the limb 2, with the contactsprings l4 and 16 lying generally parallel thereto, and extending at their contact end beyond the knife edge 3. The moving contact springs 16 carry a moulded block 18 of insulating material positioned towards their contact carrying ends, and a flat armature 19 is secured to the block 18 by rivets so that one end of the armature l9 rests against the knife edge 3 and the other through suitable holes in the yoke member 1'.

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end of the armature 19 is spaced apart from the adjacent end of the pole piece 9, which forms a pole face 20.

The gap between the armature l9 and the pole 2% may be adjusted by altering the position of the pole piece 9 so that it overhangs the middle limb 3. I

The relay functions in the following manner. When only one winding 6 is energised the limb 2 or '3, on which the other winding 6 is supported provides a path for the magnetic flux in parallel with the path through the arm ture 19, and the armature 19 does not operate. When both windings 6 are energised the magnetic flux produced by each winding 6 shares a common path through the armature l9 and the combined flux causes the armature 19 to pivot on the knife edge 8 until it rests against the pole face 29. In so doing the armature 19 causes the moving contact springs 16 to engage with the co -operating fixed contact springs 14. The relay may be provided with suitable hold winding or windings connectable to a source of energising current by means of its own contact carrying springs.

A plurality of relays according to the invention can be formed in to a multiple relay assembly by fastening a natively, as shown in the accompanying drawing, to which reference will now be made, three parallel rows of limbs 2,3 and 4 are formed integral with a common yoke member l, for example by making a plurality of transverse'cuts therein and bending the portions of the memher 1' between the cuts to form the upstanding limbs 2, 3 and 4. Bobbins 7 carrying energising windings 6' are fitted on all the limbs 3 forming the middle row and on all the limbs Z'forming one outer row, wiring tags 21 on the bobbins 7' being arranged to project downwardly A common non-magnetic member 1b is employed to clamp the separate pole pieces 9 to the limbs. 2, and 3" which they bridge and a common strip 12' of deformable material trapped between the lower faces of the pole pieces 9 and the upper ends of the bobbins 7' prevents the movement of the bobbins '7' on the limbs 2 and 31. Moving contact springs 16 of all the relays are supported by a common moulded strip 17 of insulating material, the moving contact springs 16 particular to a relay carrying a separate moulded block 18' to which an armature 19" of that relay is fastened. Fixed contact springs 14- of all the relays are supported by a similar common moulded strip 15. Both moulded strips 17 and 15 are secured to the row of limbs i, so that the contact carrying ends of the springs 14 and 16 project beyond knife edges 8 on the limbs 4, and each armature l9 rests against as associated knife edge ti and is spaced from the adjacent end or an associated pole piece 9' which forms a pole face 20'. Each relay is operated separately in the manner previously described. r

Such a multiple relay assembly is particularly suitable for use in a coordinate switching system as described in our co-pen-ding patent application No. 59,300, filed September 29, 1960. The downwardly projecting coil tags 21 facilitate the described interconnection between the windings which may be carried out, for example, by straight pieces of bare wire, or by printed circuit cards.

The described form of construction facilitates the easy removal and replacement of energising windings and spring sets for the purpose of inspection or repair.

Although the relays described in the foregoing have spring set combinations each of one fixed and one moving contact spring which combinations may form either make contacts as depicted or break contacts, it will be appreciated that by the addition of a further insulating 1 3 1 strip supporting further fixed contact springs, change over contacts of known typenray be provided.

' What I claim is: v

1. An electromagnetic relay comprising an E-shaped electromagnet having a yoke portion, two outer limbs and the armature. I

2. .An electromagnetic relay comprising an E-shaped electromagnet having a yoke portion, two outer limbs and t2. middle limb and having energizing windings on its middle limb and on .one outer limb, a contact springset comprising at least one moving contact spring which extends generally parallel to the limbs of the electromagnet, a flat armature carried by said moving contact spring and rockably engaginga knife edge on the free end of the other outer limb to form a magnetic extension thereof, and 1a pole-piece with which said armature cooperates, said polepiece bridging the limbs which have said energizing windings thereon and extending beyond the middle limb towards the armature.

3. An electromagnetic relay comprising an E-shaped electromagnet having a yoke portion, two outer limbs and i a middle limb and having energizing windings on its middle limb and on one outer limb, a contact sp-ringset comprising fixed and moving contact springs which extend generally parallel to the limbs of the electromagnet, a flat armature carried by said moving contact springs and rockably engaging a knife edge on the free end of the other outer limb to form a magnetic extension thereof, and a pole-piece with which said armature cooperates, said polepiece bridging the limbs which have said energizing windings thereon and extending beyond the middle limb towards the armature. l

4. An electromagnetic relay comprising an E-shaped electromagnet having a yoke portion, two outer limbs and a middle limb and having energizing windings on its middle limb and on one outer limb, a contact springset comprising fixed and moving contact springs secured to the other outer limb with said springs extending generally parallel thereto, a fiat armature carried by one or more of said moving contact springs and rockably engaging a knife edge provided on the free end of said other outer 3,102,934c j p limb in a position facing away from the limbs which have energizing windings thereon, and a pole-piece with which said armature cooperates, said pole-piece bridging the limbs which have said energizing windingsthereon and extending beyond the middle limb towards the armature.

5. An electromagnetic relay as claimed in olai1n4 including an insulating block carried by one or more of said moving contact springs, said insulating block carrying said armature.

6. A multiple relay assembly comprising a plurality of relays as claimed in claim 1, and a common magnetic member to which the yoke portions of the several relays are fastened.

7. A multiple relay assembly comprising :a plurality of E-shaped electromagnets each having a yoke portion, two outer limbs and a middle limb, and each having energizing windings on its middle limb and one outer limb, a common magnetic member'constituting said yoke portions, a plurality of contact springsets each particular to an'el ectromagnet and each having fixed and moving contact springs which extend generally parallel to the limbs of that electromagnet, and a plurality of flat armatures each carried by one or more moving contact springs of a springset and rockably engaging a knife edge on the free end of the other outer limb of an electromagnet to form a magnetic extension thereof, and a plurality of polepieces with which said armatures cooperate, each said pole-piece bridging the limbs which have energizing windings thereon and extending towards an armature.

8. A multiple relay assembly as claimed in claim 7 including a common non-magnetic member which clamps the pole-pieces of the several electromagnets to the limbs which they bridge. I

9. A multiple relay assembly as claimed in claim 7 in which the several springsets comprise a common insulating member for supporting the moving contact springs and a common insulating memberfor supporting the fixed contact springs. 7

References Cited in the tile of this patent UNITED STATES PATENTS Mekelburg May 2, 1961 

1. AN ELECTROMAGNETIC RELAY COMPRISING AN E-SHAPED ELECTROMAGNET HAVING A YOKE PORTION, TWO OUTER LIMBS AND A MIDDLE LIMB AND HAVING ENERGIZING WINDINGS ON ITS MIDDLE LIMB AND ON ONE OUTER LIMB, A CONTACT SPRINGSET COMPRISING AT LEAST ONE MOVING CONTACT SPRING WHICH EXTENDS GENERALLY PARALLEL TO THE LIMBS OF THE ELECTROMAGNET, A FLAT ARMATURE CARRIED BY SAID MOVING CONTACT SPRING AND ROCKABLY ENGAGING THE OTHER OUTER LIMB OF THE ELECTROMAGNET TO FORM A MAGNETIC EXTENSION THEREOF, AND A POLE-PIECE WITH WHICH SAID ARMATURE COOPERATES, SAID POLE-PIECE BRIDGING THE LIMBS WHICH HAVE SAID ENERGIZING WINDINGS THEREON AND EXTENDING BEYOND THE MIDDLE LIMB TOWARDS THE ARMATURE. 